(The half-life of Carbon-14 is 5,715 years)
A) 1,420 years
B) 7,145 years
C) 11,430 years
D) 12,855 years
An artifact has a carbon 14 to carbon 12 ratio that is 1/4 the carbon-14 to carbon-12 ratio of a similar modern object. How old is it?
2016-02-26 6:48 pm
回答 (2)
2016-02-26 7:12 pm
In a mixture of C-12 and C-14, the percentage of C-12 is close to 100%.
Therefore, the ratios of (C-14 to C-12) is close to the ratios of amounts of C-14.
The amount of C-14 in the artifact is 1/4 of that in a modern object.
(1/2)ⁿ = 1/4
No. of half-lives, n = 2
Age of the artifact
= 5715 × 2 years
= 11,430 years
...... The answer is C) 11,430 years
Therefore, the ratios of (C-14 to C-12) is close to the ratios of amounts of C-14.
The amount of C-14 in the artifact is 1/4 of that in a modern object.
(1/2)ⁿ = 1/4
No. of half-lives, n = 2
Age of the artifact
= 5715 × 2 years
= 11,430 years
...... The answer is C) 11,430 years
2016-02-26 7:11 pm
0.25 = (0.50)^(t/5715)
t = 11,430 years
C)
t = 11,430 years
C)
收錄日期: 2021-04-18 14:32:42
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20160226104801AA328j2